In rare cases, children can develop allergies to previously tolerated foods after receiving blood products via transfusion, according to a case study published in Canadian Medical Association Journal.
“It is very unusual to identify someone who experienced passive transfer of allergy from blood products,” said study author Julia Upton, MD, of The Hospital for Sick Children in Toronto, Ontario, Canada.
“Importantly, this condition has an excellent prognosis and typically resolves within a few months.”
Dr Upton and her colleagues found that blood donors who have food allergies can transfer immunoglobulin E, an antibody that reacts against allergens, from blood products such as platelets, although this is rare.
The researchers said it is important for parents and physicians to be aware of this event in case children have anaphylactic reactions after receiving blood products, particularly after eating peanuts, tree nuts, and fish, foods they could previously consume without reaction.
These reactions—with symptoms such as facial swelling, throat discomfort, or sudden fatigue—should be treated immediately at an emergency department.
When there is passive transfer of allergies after blood transfusion, physicians should follow up with the family after a few months to decide the timing of careful reintroduction of the temporary allergens into a child’s diet.
Physicians should report suspected cases of passive transfer of allergies to the hospital’s transfusion service to investigate the cause and ensure the safety of the country’s blood supply.
